DE1225166B - Process for the production of imidochlorides and / or hydrochloric acid salts of imidochlorides - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

DESIGN SCREEN

Int. Cl .:

C07c

C07d
German class: 12 ο - 22

Number: 1225 166

File number: St 18494IV b / 12 ο

Filing date: October 30, 1961

Opening day: September 22, 1966

The invention relates to a process for the preparation of imidochlorides and / or hydrochloric acid salts of imidochlorides, with the exception of the compounds in which both the carbon and the nitrogen atom of the carbonimide group are directly connected to aryl or alkaryl groups. ^: This description includes compounds with one of the following general formulas

; c -C = N-R '"

Cl

(a)

in which R, R ', R " and R'" represent identical or different alkyl, aryl, aralkyl or alkaryl groups;

R-C = N-R '

Cl

(b)

in which R is an aryl or alkaryl group and R 'is an alkyl or aralkyl group;

Process for the production of imidochlorides
and / or hydrochloric acid salts of imidochlorides

Applicant:

Stamicarbon N.V., Heerlen (Netherlands)

Representative:

Dr. F. Zumstein,

Dipl.-Chem. Dr. rer. nat. E. Assmann

and Dipl.-Chem. Dr. R. Koenigsberger,

Patent Attorneys, Munich 2, Bräuhausstr. 4th

Named as inventor:

Johannes Hubertus Ottenheym, Sittard;

Johan Willem Garritsen, Geleen (Netherlands)

Claimed priority:
Netherlands of October 31, 1960 (257 446,
257447)

R '

: CH - C = N-R " Cl

in which R, R 'and R "represent identical or different alkyl, aryl, aralkyl or alkaryl groups;

R-CH ₉ -C = N-R '

Cl

(d)

in which R and R 'are identical or different alkyl, aryl, Represent aralkyl or alkaryl groups and R can also be a hydrogen atom;

H-C = N-R

Cl

(e)

in which R represents an alkyl, aryl, aralkyl or alkaryl group;

C ==

= N

(f)

Cl

in which η has a value> 2.

It is known that some of these imido chlorides can be prepared by reacting corresponding N-monosubstituted acid amides with phosphorus chlorine compounds such as PCl ₅ , PCl ₃ , POCl ₃ or mixtures of these compounds. This method of preparation has the disadvantage that by-products are formed in the form of phosphorus-containing compounds, which have to be removed from the reaction mixture, which entails additional processing in the purification of the desired end product. In addition, especially in the case of the imidochlorides covered by the above general formulas (d), (e) and (f), it has mostly proven impossible to isolate the imidochlorides and / or their hydrochloric acid salts from the reaction mixtures obtained, since these Substances have a very strong tendency to decompose.

It has also been proposed (Hevetica Chimica Acta, 42 [1959], 1659 ff.), In particular for production of the imidochlorides covered by the above general formulas (b), (d), (e) and (f) are to add phosgene to a solution of the corresponding N-monosubstituted acid amides. According to However, this process produces only a low yield of the imidochlorides (e.g. 2-chlorazacyclohepten-1,2 from ε-caprolactam with an efficiency of 28%). It could also

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3 4

in this method, it cannot be proved that R "therein is an aryl or alkaryl group

the imidochlorides in question and / or their represents] are recorded. It is then also advisable to

have actually formed hydrochloric acid salts, since during the production of these groups of imido-

neither the reaction products of the phosgenation chlorides to ensure that during the whole

reaction immediately converted into more stable products, the amount of phosgene present was in the course of the reaction

the or products have been isolated which is not at least 1.8 mol. On the other hand, it has

clearly as imidochlorides and / or their hydrochloric acid preference, in the production of the other imido-

Salts were to be identified. chloride throughout the course of the reaction

It has now been found that the amount of phosgene present in imido decreases, namely

chloride and / or hydrochloric acid salts of imidochlori- io to 1 to 1.3 mol per mol of acid amide.

den, except for the imidochlorides, in which so- It is not necessary to use the phosgene

probably the carbon as well as the nitrogen atom of any small ones previously contained therein

to free the carbonimide group directly with aryl or amounts of hydrogen chloride. Preferably

Alkaryl groups are connected, in a simple manner this should even be omitted, since it has been found

and in good yield by reaction of the corresponding 15 that the reaction is catalyzed by hydrogen chloride

corresponding N-monosubstituted acid amides with phosphate is siert.

produce gene in the presence of a solvent The process according to the invention is allowed to pass, in such a way that during the leads in the presence of a solvent for the throughout the course of the reaction at least 1 mole of phosgene, which is not under the reaction conditions Phosgene is present per mole of acid amide with which 20 reacts and is preferably also capable Provided that in the implementation of acid amides to be dissolved in the acid amide. Suitable solvents those on the next to the carbon atom of the car are e.g. hydrocarbons, such as benzene and tobacco group lying carbon atom at least luene, and in particular halogenated hydrocarbons-1 Hydrogen atom is bonded or in which the substances such as chloroform, carbon tetrachloride, chlorocarbonamide group with only one hydrogen atom 25 benzene and dichlorobenzene.

It is advisable to carry out the reaction under atmospheric action at most 2 moles of phosgene per mole of amidic pressure, whereby a simple one is present. Apparatus is possible. However, it can also be advantageous during this reaction, as a side effect, to produce a somewhat productive CO ₂ during the reaction, which can easily be released from the reaction mixture 30 at a high pressure of e.g. B. ¹ U, V2 or 1 at, escapes, and HCl, which can also escape. The reaction temperature can be a salting of the imidochloride with the resulting imidochloride, which forms acidic salt from the initial. If the latter is the case, the aforementioned general formulas (a), (b) and (c) [precipitated in the hydrochloric acid salt and in the latter case as such, provided that R ″ therein represents an aryl or alkaryl group is] detected fairly the process of the invention will vary in the ^star k and for example, executed at a value between a way that are kept throughout the reaction O and 10O ⁰ C,. but it is also tion course of at least 1 mole of phosgene per Even higher temperatures are permissible below 0 ° C. Acid amide is present, which is the case for acid amides, in most cases the reaction rate is too slow for the carbon atom next to the carbon atom What- in the first reaction stage, in which the reaction hydrogen atom is bound, means that either components are brought together, the temdas acid amide gradually a solution of the total temperature to one m lower value of z. B. 20 to th amount of phosgene is added or to keep the two 40 ° C and then z. B. to 40 to increase reaction components in at least equimolecular 45 100 ° C, specifically for the purpose of a larger amount at the same time a reaction zone pulling reaction, in which as complete a conversion as possible is carried out. is aimed.

On the other hand, in the case of the other acid amides, the same applies to the preparation of the other imidochlorides

Process carried out in such a way that during the reaction temperature is, however, to avoid

During the entire course of the reaction, at most 2 moles of phosphorus formation of side reactions, preferably below 40.degree

genes per mole of acid amide are present because kept at, but generally not below 0 ° C. A

larger amounts of phosgene these acid amides under preferred embodiment of the method for

Formation of N-substituted carbamyl chlorides react. Production of these imidochlorides consists in that

The latter reaction was already mentioned in the name of the reacting constituents, namely the acid

Belgian patent holder 55 amide, or a solution of the same, and a solution

writing 582478 for the production of 2-chloraza from phosgene, simultaneously in a continuous manner cyclo-2,3-alkene-l-carbochlorides are fed based on a reaction zone in which the

cü lactams described. At the acid temperature mentioned is 20 to 40 ° C and from which the

The process can therefore only remove amides in the way that reaction product is continuously removed and the same

be carried out that the two reaction 60 then down to a temperature below 20 ° C-

components of a reaction zone is train-cooled at the same time.

in such a proportion that in view of the great sensitivity of the per mole of at least 1 and at most 2 moles of phosgene imidochlorides, or their hydrochloric acid salts, for

are fed. Moisture, it is advisable to keep the entire

The formation of imidochlorides from N-substitution with as complete an exclusion as possible of

ated acid amides is hardest to take place with the imido moisture and also the chlorid, the substances generally formed by the aforementioned, with the exclusion of moisture

formulas (a), (b) and (c) [in the latter case, to be retained.

According to the process according to the invention, as said, the imidochlorides and / or their hydrochloric acid salts in a simpler manner and generally in greater yield than according to the known Technology to be produced. There is also the possibility according to the invention of a number of Imidochlorides, either as such or in the form of their hydrochloric acid salts, isolate their existence has only been accepted so far, but was not detectable, or which is not yet known at all was.

The imidochlorides and / or hydrochloric acid salts of imidochlorides prepared according to the invention are valuable intermediate products from which, through further reactions, important substances are made can be won. So z. B. by reaction with primary or secondary Amines Make amidines, which are used in the manufacture of dyes and medicines. By reaction with chlorine gas or another chlorinating agent and subsequent hydrolysis The imidochlorides can be covered by the general formulas (d) and (f) mentioned at the outset become, to α, α-dichloramides, or α, α-dichlorolactams are converted from which, through further reactions, amino acids that are important for food are formed or have high molecular weight products made with plastic properties.

The resulting imidochlorides and / or hydrochloric acid salts can under certain circumstances occur through recrystallization or purified by distillation and in such a state with complete exclusion of moisture can be kept for a shorter or longer period of time, but in many cases such No cleaning, because the substances produced according to the invention easily become one suitable for further implementation. It is even advisable to use the imidochlorides, which are different from those mentioned at the beginning. general formulas (c) [insofar as R "represents an alkyl or aralkyl group], (d), (e) and (f) can be detected without subjecting a series of other reactions without further purification in order to avoid losses due to intermediate decomposition to a minimum. A possibly applied Excess phosgene, like the solvent used, is recovered and can be used up new ones are needed.

It has been found that the acid amides of aromatic or alkyl aromatic carboxylic acids, in which the nitrogen atom is also attached to an aryl or alkaryl group, under the proportions of the invention do not react with phosgene. The making of this group of compounds is therefore not the subject of this property right.

The invention is explained in more detail with reference to the following exemplary embodiments.

example 1

400 ml of benzene, in which 150 g of phosgene is dissolved, are passed into a spherical reaction vessel with a capacity of 11, which is provided with a stirrer and a reflux condenser through which ice water is pumped for the duration of the experiment. A solution of 78.5 g of N-butyl-pivalamide (N-butyl-trimethylacetamide) in 150 ml of benzene is added to this solution over a period of 1 hour, the temperature in the reaction vessel being kept at 30 to 40 ° C. The temperature in the reaction vessel is then kept at 30 to 40 ° C. The temperature of and is then kept at this value for 4 hours, and the reaction mixture is increased up to 40 to 60 ^° C., during which time part of the excess of phosgene is distilled over.

After the reaction has ended, the remaining phosgene and benzene are reduced by distillation normal pressure removed. The residue is taking

ίο a pressure of 12 mm Hg fractionated. At 65 ° C., the resulting N-butyl pivalimidochloride distills over as a colorless liquid with the refractive index η ² S = 1.4440 (54.5 g). An unreacted amount of N-butyl-pivalamide of 26.3 g then distilled over at 120 to 122 ° C. The efficiency - calculated on the converted acid amide - is 93.4%. The substance is identified with the help of elemental analysis and infrared spectrometry.

Example 2

In the reaction vessel used in Example 1 250 ml of chloroform are passed, whereupon in this Substance 250 g of phosgene are dissolved. This solution becomes a solution over a period of 1 hour of 163 g of N-propylbenzamide in 250 ml of chloroform were added, the temperature in the reaction vessel being kept at 25 to 30 ° C. Afterward the temperature of the reaction mixture is gradually increased up to 60 ° C in 1.5 hours and held at this value for 4 hours.

After the reaction has ended, the remaining phosgene and chloroform are removed by distillation under normal pressure and the residue is distilled under a pressure of 2 mm Hg. The resulting N-propyl-benzimidochlorid distilled at 84 ⁰ C as a colorless liquid with refractive index n ² g = 1.5421 on. The yield is 179 g, which corresponds to an efficiency of 98.6%. The substance is identified with the help of elemental analysis and infrared spectrometry.

Example 3

In the same way as described in Example 2, a solution of 135 g of N-methylbenzamide in 150 ml of chloroform is added to a solution of 200 g of phosgene in 400 ml of chloroform over a period of 1 hour at room temperature. The temperature is then gradually increased up to 60 ^° C. and held at this value for a further 5 hours.

After removing the remaining phosgene and chloroform by distillation under normal pressure, the residue is distilled under a pressure of 1 mm Hg. At 67 ° C, the N-methylbenzimidochloride distills over as a colorless liquid with a refractive index nf - 1.5625. The yield is 149 g, which corresponds to an efficiency of 97.1%. The substance is identified by means of elemental analysis and infrared spectrometry.

Example 4

The reaction vessel used in Example 1 are simultaneously in a period of 1 hour a solution of 100 g of phosgene in 200 ml of chloroform and a solution of 81.5 g of N-phenyl-isobutyramide added in 200 ml of chloroform, the temperature in the reaction vessel at 25 to 30 ° C ge

will hold. The temperature of the reaction mixture is then gradually increased to within 2Va hours increased to 60 ° C and held at this value for 3 hours.

After the reaction has ended, the remaining phosgene and chloroform are removed by distillation under normal pressure and the residue is distilled under a pressure of 3 mm Hg. The resulting N-PhenyWsobutyrimidochlorid distills at 76 ° C as a colorless liquid with a refractive index η ² S = 1.5380. above. The yield ages 70.5 g, which corresponds to an efficiency of 77.7%. The substance is identified with the help of elemental analysis and infrared spectrometry.

Example 5

In the same way as described in Example 4, a solution of 100 g of phosgene in 250 ml of chloroform and a suspension of 101.5 g of N-phenylhexahydrobenzamide in 250 ml of chloroform are added to the reaction vessel over a period of 1 hour, the temperature in Reaction vessel is kept at 35 ° C. The temperature is then gradually increased in 2 hours up to 55 to 6O ⁰ C and then held still for 3 hours at this value.

After distilling off the excess of phosgene and chloroform under normal pressure, the residue is distilled at a pressure of 1 mm Hg. The resulting N-phenylhexahydrobenzimidochloride distills over at 122 to 123 ° C as a colorless liquid (nf = 1.5528). The yield is -90 ^; -g, which corresponds to an efficiency of 81.3% w'The substance is identified by means of elemental analysis and infrared spectrometry.

Example 6

The same reaction vessel as used in the previous examples are used in one For a period of 1 hour at a temperature of about 20 ° C., a solution of 55 g of phosgene in 300 ml dry ether and a solution of 64.5 g of N-butylpropionamide added in 150 ml of dry ether. Then for 5 hours at Allowed to react at room temperature, whereupon the remaining phosgene with the help of dry nitrogen and the ether removed from the reaction vessel and the last traces by means of a high vacuum pump be driven out.

The remaining light yellow liquid weighs 73.5 g (i.e. the theoretical yield) and with the help of a chlorine determination and infrared spectrometry as N-butyl-propionimidochlorid identified.

Example?

The reaction vessel used in the previous examples are used in a period of 1 hour at a temperature of about 20 ° C, a solution of 55 g of phosgene in 300 ml of carbon tetrachloride and a solution of 57.5 g of N-propylpropionamide in 150 ml of carbon tetrachloride was added, whereupon the reaction is allowed to continue for a further 5 hours at room temperature. With the help of dry The remaining phosgene and carbon tetrachloride are then expelled and by means of nitrogen a high vacuum pump removed the last traces. The weight of those left behind, pale yellow Liquid is 68.5 g, slightly more than the theoretical yield, indicating a small amount Carbon tetrachloride is due, which is not completely removed even in a high vacuum. the end Identification by means of infrared specktrometry shows that the substance is N-propyl propionimidochloride.

Example 8

iö In the same way as in the previous examples are described, the reaction vessel over a period of 1 hour at a temperature from about 20 ° C a solution of 100 g of phosgene in 250 ml of chloroform and a solution of 67.5 g Acetanilide added in 250 ml of chloroform. Already after half an hour it forms with the development of heat a solid crystalline substance in the reaction mixture. After a post-reaction time of This solid substance is filtered off in an atmosphere of dry nitrogen for 3 hours at 25 to 30 ° C and dried. The weight of this substance is 51.5 g and the melting point 119 to 121 ° C. According to Mixing with the hydrochloric acid salt of acetanilide does not lower the melting point. Also from infrared spectrometry reveals the identity of both substances. The amount of isolated salt corresponds to 60% of the starting product.

The mother liquor of the filtered product gives after evaporation in vacuo at a temperature of 20 to 30 ° C a residue of 30 g of light yellow liquid, which is very hygroscopic and unstable is. With the help of infrared spectrometry, this substance is shown as an almost pure N-phenyl-acetimido- ■ chloride identified. The efficiency is - based on acetanilide - about 39%.

For the imide chlorides prepared according to Examples 6, 7 and 8, the identification is as follows verifiable:

In all three cases, an amidine was prepared from the end product according to the procedure given in Example 11. The following were obtained:

Example 6

N - butyl - N '- phenylpropionamidine, boiling point 142 ° C at 1 mm Hg.

Example 7

N-propyl-N'-phenylpropionamidine, boiling point 122 ° C at 1 mm Hg.

Example 8

N-N'-diphenylacetamidine, melting point 131 to 132 ° C.

Example 9

The reaction vessel used in the previous examples will be used in a period of time a solution of 59 g of N-methylformaldehyde in 200 ml of benzene for 1 hour at room temperature and a solution of 200 g of phosgene in 300 ml of benzene was added. The reaction mixture is then brought to a temperature of about 40 ° C and held at this value for a further 5 hours.

After the reaction has ended, the remaining phosgene is expelled using dry nitrogen and the resulting precipitate is filtered off in a nitrogen atmosphere and dried. It forms

70 g of white crystalline product with a melting point of 160 to 162 ° C, which with the help a chlorine determination and infrared spectrometry as the hydrochloric acid salt of N-methylformimidochloride is identified. The efficiency is - based on N-methylformamide - so 61.4%.

Example 10

The reaction vessel used in the preceding examples are at a temperature of about 20 ° C in a period of 1 hour, a solution of 56 g of phosgene in 400 ml of carbon tetrachloride and a solution of 56.5 g of ε-caprolactam in 150 ml of carbon tetrachloride was added. Afterward is left to react further for 6 hours at this temperature.

After the reaction, the precipitate formed is dried in an atmosphere of nitrogen filtered off and dried. 76 g of white crystalline product with a melting point are precipitated (determined in a closed tube) from 66 to 70 ° C. Using chlorine determination and infrared spectrometry the substance is called the hydrochloric acid salt of 2-chloro-azacyclohepten-1,2 (caprolactimimidochloride) identified. The efficiency is thus 90.5%, while still in the mother liquor a lot of this salt remains in a dissolved state.

The importance of the method according to the invention becomes particularly clear when compared with the Method according to German patent specification 917 669, where in the case of obvious non-compliance with the invention Reaction conditions from the same reactants other substances are formed.

Example 11

A cylindrical reaction vessel with a capacity of 50 ml is with a stirrer, a reflux condenser, through which ice water is pumped for the duration of the experiment two inlet openings on the upper one and one outlet opening on the lower one Side. 25 ml of chloroform are put into the vessel and then a solution of 57.5 g at the same time over a period of 1 hour N-propyl-propionamide in 150 ml of chloroform and a solution of 50 g of phosgene in 150 ml of chloroform introduced while the reaction mixture is continuous at the lower side in the manner continuously is discharged that the vessel always remains half full. The temperature in the reaction vessel is kept at 20 to 25 ° C; the discharged The reaction mixture is collected in a collecting vessel kept at about 18 ° C., which is equipped with a Ventilation is equipped, on which there is a pipe with a desiccant.

After the reaction has ended, the resulting N-propyl-propionimidochloride is then converted into the corresponding amidine by adding the entire contents of the collecting vessel over a period of 1 hour to a solution of 140 g of aniline in 250 ml of chloroform obtained by stirring. The temperature is kept at about 30.degree. C., and after adding the imidochloride, the reaction continues for half an hour at about 40.degree. The reaction mixture is then separated into two layers, the aqueous layer is made alkaline with a sodium hydroxide solution and then extracted with benzene. The solvent is distilled off from the benzene solution obtained in this way under normal pressure and the residue is distilled under a pressure of 1 mm Hg. After a first run of aniline, the N-propyl-N'-phenyl-propionamidine distills over at 122 ° C. as a colorless oil (nf = 1.5510). The yield is 77 g, which - based on N-propyl-propionamide - is equivalent to an efficiency of 81.0%. The yield of imidochloride is therefore a minimum of 81%. The amidine is characterized with the help of elemental analysis and infrared spectrometry

Example 12

In the same reaction vessel and in the same way as described in Example 11, one leaves in a solution of 56.5 g of ε-caprolactam in 150 ml of chloroform with a period of 1 hour

ao of a solution of 50 g of phosgene in 150 ml of chloroform react at a temperature of 20 to 25 ° C. The discharged reaction mixture is in collected in a collecting vessel kept at about 18 ° C.

After the reaction has ended, the resulting 2-chloro-azacyclohepten-1,2 is converted into the corresponding Amidine is transformed by taking the entire contents of the collecting vessel in the same way as in the example 11 described, allowed to react with 140 g of aniline in 250 ml of chloroform and the reaction mixture processed in the same way. The 2-anilidoazacycloheptene-1,2 distilled under a pressure of 1 to 2 mm Hg at 126 to 128 ° C over as a colorless oil that solidifies into a solid substance with a melting point of 102 ° C. After recrystallization a white crystalline substance with a melting point of 105 ° C. precipitates from cyclohexane which is further characterized by elemental analysis. The yield is 81 g, what - based on ε-caprolactam - corresponds to an efficiency of 86.2%. The yield of imidochloride is therefore at least 86.2%.

Example 13

In the same way as described in Example 12, a solution of 2-chloro-azacyclohepten-1,2 in chloroform is prepared by starting from 113 g of ε-caprolactam in 250 ml of chloroform and 100 g of phosgene in 250 ml of chloroform. Chlorine gas is then introduced into this solution at such a rate that this gas is completely absorbed. The temperature of the solution is kept below 30 ^° C. When no more chlorine is taken up (after about ½ hour), the reaction mixture is kept at a temperature of 25 ° C. for a further hour, after which the chloroform is distilled off at a temperature below 40 ° C. under reduced pressure. The liquid residue is poured over ice, and after stirring for 1 hour, the water is decanted and the remaining crystal pulp is filtered off, washed out with cold ether and dried. 128 g of α, α-dichlorocaprolactam with a melting point of 122 to 123 ° C. are obtained. The efficiency is - based on ε-caprolactam - 70.3%.

In a corresponding experiment, the chlorination is carried out by adding the solution of the imidochloride in 11 sulfuryl chloride for 2 hours

60S 667/432

at 25 to 30 ° C, then gradually increasing the temperature of the reaction mixture in 2 hours increases to 60 ° C and holds at this value for 1 hour. After the chloroform has been distilled off and the excess of sulfuryl chloride under reduced pressure, pouring on ice, decanting, Filtering off, washing out and drying, the yield is 160 g of α, α-dichlorocaprolactam with a Melting point from 121 to 122 ° C. Efficiency .88.0%.

The production of amidines or of α, α-dichlorocaprolactam according to Examples 6 to 8 and to 13 is used to characterize the produced Imide chlorides. It is not the subject of this property right.

Claims (4)

Patent claims: 1. Process for the production of imidochlorides and / or hydrochloric acid salts of imidochlorides, with the exception of the imidochlorides, in which both the carbon and the nitrogen atom of the carbonimide group are directly are linked to aryl or alkaryl groups by reaction of N-monosubstituted acid amides with phosgene in the presence of a solvent, characterized in that during the entire course of the reaction at least 1 mole of phosgene per mole of acid amide is present, with the proviso that upon implementation of acid amides, in which the one lying next to the carbon atom of the carbonamide group Carbon atom is bonded to at least 1 hydrogen atom or in which the carbonamide group is connected to only one hydrogen atom during the entire course of the reaction at most 2 moles of phosgene are present per mole of acid amide. 2. The method according to claim 1, characterized in that during the implementation of Acid amides in which the carbon atom lying next to the carbon atom of the carbonamide group no hydrogen atom is bonded, at least 1.8 mol of phosgene are present per mol of acid amide. 3. The method according to claim 1, characterized in that during the implementation of Acid amides, in which the next to the carbon atom The carbon atom lying on the carbonamide group only has 1 hydrogen atom and an aryl or alkaryl group is bonded to the nitrogen atom is, per mole of acid amide 1.8 to 2.0 mol of phosgene are present. 4. The method according to claim 1, characterized in that during the reaction of Acid amides, in which the one lying next to the carbon atom of the carbonamide group Carbon atom only 1 hydrogen atom and on the nitrogen atom an alkyl or aralkyl group is bonded or in which to the next to the carbon atom of the carbonamide group lying carbon atom 2 hydrogen atoms are bonded or in which the carbonamide group is connected to only one hydrogen atom, 1.0 to 1.3 mol of phosgene per mol of acid amide is available. 5. The method according to claim 1 to 4, characterized in that in the presence of a solvent, which under the reaction conditions both the phosgene and the acid amide solves, is worked. 6. The method according to claim 1 to 5, characterized in that the reaction takes place under atmospheric conditions Printing is carried out. 7. The method according to claim 1, 2, 3, 5 or 6, characterized in that the temperature of the reaction mixture is kept at a value between 0 and 100 ° C during the reaction of the acid amides mentioned in claims 2 and 3. 8. The method according to claim 7, characterized in that in the initial stage of the reaction the temperature of the reaction mixture to a value between 20 and 40 ° C and later is kept at a value between 40 and 100 ° C. 9. The method according to claim 1, 4, 5 or 6, characterized in that in the reaction the acid amides mentioned in claim 4, the temperature of the reaction mixture on a Value is kept between 0 and 40 ° C. 10. The method according to claim 9, characterized in that the reacting constituents be fed simultaneously in a continuous manner to a reaction zone in which the temperature is kept at a value between 20 and 40 ° C and from which the reaction product continuously expelled and immediately cooled to a temperature below 20 ° C. 11. The method according to one or more of claims 1, 4, 5, 6, 9 and 10, characterized in that that 2-chloro-azacyclohepten-1,2 (caprolactimimidochloride) and / or the hydrochloric acid salt of 2-chloro-azacyclohepten-1,2 is made. Considered publications:
German patent specifications No. 917 669, 566 603,
588; Belgian Patent No. 582,478;
U.S. Patent No. 2,836,592;
Helvetica Chimica Acta, 42 (1959), pp. 1659 ff .;
PhD thesis HR Meyer, Zurich, 1956, Houben-Weyl, Methods of Organic Chemistry, 4th edition, Vol. 11/2, p. 57; J. Am. Chem. Soc, 80, pp. 6233/7 (1958);
Liebigs Analen der Chemie, 453 (1927), pp. 113 to 147. 609 667/432 9.66 © Bundesdruckerei Berlin